Ubale umodzi ndi ambiri m'mabuku ake amapezeka pamene malemba onse omwe ali mu Table A angakhale ndi zolemba zambiri zogwirizana pa Table B, koma zolembedwa zonse mu Table B zingakhale ndi imodzi yokha yovomerezeka mu Table A. Chiyanjano chokha ndi zambiri malo osungirako zinthu ndidongosolo lodziwika bwino lomwe limagwirizanitsa machitidwe azinthu ndipo ali pamtima wokongola.
Ganizirani mgwirizano pakati pa mphunzitsi ndi maphunziro omwe amaphunzitsa. Aphunzitsi angaphunzitse maphunziro angapo, koma maphunzirowo sangafanane ndi aphunzitsi.
Choncho, pa kafukufuku uliwonse mu tebulo la Aphunzitsi, pakhoza kukhala zolemba zambiri mu gome la maphunziro. Uku ndi ubale umodzi ndi ambiri: mphunzitsi mmodzi ku maphunziro angapo.
Chifukwa chiyani kukhazikitsa mgwirizano umodzi ndi wambiri ndi wofunikira
Kuimira ubale umodzi mpaka ambiri, mukufunikira ma tebulo awiri. Tiye tione chifukwa chake.
Mwina tinapanga tebulo la aphunzitsi limene tinkafuna kulemba dzina ndi maphunziro omwe amaphunzitsidwa. Titha kupanga izi monga izi:
Mphunzitsi_ID | Teacher_Name | Inde |
---|---|---|
Mphunzitsi_001 | Carmen | Biology |
Mphunzitsi_002 | Veronica | Masamu |
Mphunzitsi_003 | Jorge | Chingerezi |
Bwanji ngati Carmen akuphunzitsa maphunziro awiri kapena angapo? Tili ndi njira ziwiri ndi kapangidwe kameneka. Tikhoza kuwonjezera pa mbiri ya Carmen yomwe ilipo, monga izi:
Mphunzitsi_ID | Mphunzitsi _Name | Inde |
---|---|---|
Mphunzitsi_001 | Carmen | Biology, Math |
Mphunzitsi_002 | Veronica | Masamu |
Mphunzitsi_003 | Jorge | Chingerezi |
Zopangidwe pamwambapa, komabe, ndizovuta ndipo zingayambitse mavuto pakapita nthawi poyesera kuyika, kusintha kapena kuchotsa deta.
Zimakhala zovuta kufufuza deta. Kukonzekera kumeneku kumaphwanya lamulo loyamba la kafukufuku wachinsinsi, Fomu Yoyamba Yoyamba (1NF) , yomwe imanena kuti selo iliyonse ya tebulo iyenera kukhala ndi deta imodzi, yosadziwika.
Chinthu chinanso chokhazikitsidwa chingakhale kokha kuwonjezera mbiri yachiwiri kwa Carmen:
Mphunzitsi _ID | Mphunzitsi _Name | Inde |
---|---|---|
Mphunzitsi_001 | Carmen | Biology |
Mphunzitsi_001 | Carmen | Masamu |
Mphunzitsi_002 | Veronica | Masamu |
Mphunzitsi_003 | Jorge | Chingerezi |
Izi zimamatira ku 1NF koma adakalibe osauka pogwiritsa ntchito deta chifukwa imayambitsa redundancy ndipo ikhoza kubisa deta yaikulu kwambiri. Chofunika kwambiri, deta ikhoza kukhala yosagwirizana. Mwachitsanzo, bwanji ngati dzina la Carmen lasintha? Wina wogwira ntchito ndi deta akhoza kusinthira dzina lake mu mbiri imodzi ndi kulephera kusinthira izo mu mbiri yachiwiri. Mapangidwewa akuphwanya Fomu Yachiwiri Yachiwiri (2NF), yomwe imatsatira 1NF ndipo imayenera kupeĊµeranso zowerengera za zolemba zambiri polekanitsa magawo a deta mu matebulo angapo ndikupanga ubale pakati pawo.
Mmene Mungapangire Chidwi ndi Maubale Amodzi Ndi Ambiri
Kuti tigwiritse ntchito ubale umodzi ndi ambiri mu tebulo la Aphunzitsi ndi Maphunziro, timaphwanya matebulo awiri ndikuwagwiritsira ntchito makiyi akunja .
Pano, tachotsa chigawo cha Kokosi pa tebulo la aphunzitsi:
Mphunzitsi _ID | Mphunzitsi _Name |
---|---|
Mphunzitsi_001 | Carmen |
Mphunzitsi_002 | Veronica |
Mphunzitsi_003 | Jorge |
Ndipo apa pali gome la maphunziro. Dziwani kuti chofunika chake chachilendo, Teacher_ID, chimayendera maphunziro kwa aphunzitsi mu tebulo la aphunzitsi:
Chifukwa_ID | Chifukwa cha_Name | Mphunzitsi_ID |
---|---|---|
Chifukwa_001 | Biology | Mphunzitsi_001 |
Chifukwa_002 | Masamu | Mphunzitsi_001 |
Chifukwa_003 | Chingerezi | Mphunzitsi_003 |
Tapanga mgwirizano pakati pa aphunzitsi ndi gome la maphunziro pogwiritsa ntchito makiyi akunja.
Izi zikutiuza kuti zonse za Biology ndi Math zimaphunzitsidwa ndi Carmen ndipo Jorge amaphunzitsa Chingerezi.
Titha kuwona momwe kapangidwe kameneka kumapezera zovuta zonse, zimaphunzitsa aphunzitsi kuti aziphunzitsa maphunziro angapo, ndikugwiritsa ntchito ubale umodzi ndi ambiri.
Mazenera angagwiritsenso ntchito ubale umodzi ndi umodzi komanso ubale wambiri mpaka ambiri.